Browse Articles

Tailoring structural and optical properties of ZnS nanoparticles via strontium doping

Nanomedicine for neuroinflammation modulation: Next-generation nano-immunotherapies for neurodegenerative disorders

Data‐Driven Accelerated Discovery of LNMCO Cathodes Materials via 37‐Dimensional Parameter Space Mining With a Cascaded Neural Network

ABSTRACT The vast, unexplored synthesis space of LNMCO cathode materials contains potential solutions to the long‐standing trade‐off between energy density and stability. To navigate this high‐dimensional space, a predictive tool capable of accurately mapping the complex relationships between synthesis parameters and electrochemical performance is essential. Here, a cascaded neural network (CaNN) architecture was designed to simulate the material synthesis workflow. This model synchronously maps 37 process dimensions within the composition‐processing‐structure‐property‐performance (CPSPP) paradigm. By utilizing a cascaded structure, the output of upstream prediction tasks serves as the input for downstream tasks, enabling the capture of hierarchical dependencies that govern material properties. This design choice proved highly effective, achieving superior predictive accuracy with an overall coefficient of determination ( R 2 ) of 0.85. Furthermore, SHAP analysis was integrated to open the model's “black box,” demonstrating a mechanism‐informed approach where predictions align closely with the underlying physical laws of structural inheritance. Experimental validation of nine candidates spanning diverse compositions and synthesis routes confirms the predictive accuracy of the strategy (prediction errors < 10%), establishing a “CaNN modeling → Latin Hypercube Sampling → Wa Screening → Experiments validation” framework for the accelerated discovery of high‐performance cathode materials.

Molecular Synergy‐Enabled Buried Interface Engineering Toward Highly Efficient and Operationally Stable Flexible Perovskite Photovoltaics

ABSTRACT Self‐assembled monolayers (SAMs) have become pivotal hole‐selective layers for efficient inverted perovskite solar cells (PSCs), yet conventional single‐component SAMs suffer from severe intermolecular aggregation, insufficient thermal anchoring, and weak crystallization templating, which severely limit efficiency and operational stability, especially in flexible configurations. Herein, we demonstrate a rationally designed molecular engineering approach for constructing robust buried bottom interfaces via multifunctional SAMs featuring bidentate phosphonic acid anchors, electron‐donating methoxy groups. Such elaborate molecular design enables strengthened interfacial binding, optimized energy‐level alignment, suppressed self‐aggregation, and oriented perovskite crystallization with relieved residual tensile strain. As a result, rigid PSCs achieve a champion efficiency of 27.15% (certified 26.51%), and flexible PSCs exhibit a remarkable efficiency of 25.37% with outstanding mechanical robustness. Moreover, the optimized devices deliver exceptional operational stability, retaining 97.5% of initial performance after 1000 h of continuous operation under ISOS‐L‐2 protocols. This work provides a universal molecular engineering paradigm toward high‐performance and ultra‐stable flexible perovskite photovoltaics via robust buried interface engineering.

Wearable Morphology‐Adaptive in‐Ear Device With Active Cleansing Capability for Multimodal Health Monitoring

ABSTRACT Multimodal physiological monitoring using in‐ear devices is an excellent solution for nonintrusive and noninvasive health monitoring. However, the small size of the ear canal, variation in its morphology in different individuals, and ear wax introduce challenges such as a non‐conformal interface between the sensors and the skin due to the complex ear canal geometry, device fitting issues, biofouling blockage layers, hearing blockage by the device and discomfort. Here, we report a multimodal self‐cleansing, in‐ear nonintrusive and configurable electronic (SCIENCE) device which adapts to various canal geometries and performs active wax cleaning at the sensor‐canal interfaces. Triggered by immersing the sensor in water, the small cylindrical device with a diameter of 2 mm expands once in the ear, and it converts to a spindle shape with a center diameter that can reach 9 mm, thus leading to adaptive contact with the ear canal and forming a stable sensor‐canal interface. The proposed in‐ear device was also endowed with wax cleaning capability to automatically break the biofouling barrier and decrease the sensor‐skin interface impedance by 20%. SCIENCE is integrated with miniaturized circuits and enables simultaneous mobile and wireless recording of electroencephalography (EEG), electrocardiography (ECG), and core body temperature.

Advances in Aerogel Materials for Energy and Environmental Sustainability

ABSTRACT Aerogels have emerged as a unique class of ultralight porous materials that combine exceptional thermal insulation with low density, high porosity, and remarkable structural versatility, enabling broad opportunities across aerospace, energy, electronics, environmental remediation, and wearable technologies. However, their widespread adoption has been constrained by the high cost, limited scalability, and energy‐intensive nature of conventional manufacturing processes, particularly supercritical CO 2 drying. This review highlights recent advances in scalable and cost‐effective aerogel fabrication, including ambient‐pressure drying, templating strategies, top‐down manufacturing, chemical vapor deposition, and solution spinning, which collectively enable enhanced performance while significantly reducing production complexity and cost. We further present a unified perspective on the thermal transport physics of porous materials by systematically discussing the mechanisms of solid conduction, gas conduction, convection, and thermal radiation, and comparing aerogels with other porous architectures such as cellular foams. These fundamental insights establish rational design principles for engineering next‐generation aerogels with tailored thermal functionalities. Finally, we showcase emerging applications that extend well beyond thermal insulation, including moisture‐ and water‐driven energy harvesting, oil–water separation, high‐temperature acoustic insulation, and thermoregulating smart textiles. By bridging scalable manufacturing, fundamental thermal science, and emerging multifunctional applications, this work provides a comprehensive framework for the rational design and commercialization of next‐generation aerogels, paving the way toward their widespread adoption in advanced materials and engineering systems.

Side‐Chain‐Induced Interlayer Slipping in Metalloporphyrin COFs Enables Microenvironment and Spin‐State Regulation for Photocatalytic CO ₂ Reduction

ABSTRACT Photocatalytic CO 2 reduction (CO 2 RR) involves a cascade of intrinsically coupled processes, rendering the independent optimization of catalytic kinetics and thermodynamics challenging. In this study, we introduce a structural regulation strategy via steric‐driven interlayer slipping engineering of metalloporphyrin‐based covalent organic frameworks (COFs) to decouple and simultaneously optimize the catalytic microenvironment and the spin state of the active metal center. Through regulating the length of alkoxy side‐chains, conventional AA stacking is transformed into a moderately serrated slipped configuration (AA*). Kinetically, the resulting slipped nanochannels enhance local hydrophobicity and spatial confinement, thereby greatly enriching in‐channel CO 2 concentration and suppressing hydrogen evolution. Thermodynamically and electronically, this interlayer slipping reconstructs the ligand field of catalytic Co sites and maximizes vertical π–d exchange interactions. As a result, this triggers a collective spin transition from isolated low‐spin ( S = 1/2) monomers to a high‐spin ( S = 3/2) state, which significantly prolongs charge carrier lifetimes and optimizes the adsorption and activation of the *COOH intermediate. Consequently, the optimized CoP‐COFs deliver a record CO production rate of 71.4 mmol g −1 h −1 with 90% selectivity among porphyrin‐based COF photocatalysts. This work establishes stacking engineering as a versatile strategy for decoupling entangled reaction steps to enable efficient solar fuel production.

Hydrogel‐Interfaced Active Rehabilitation System: From Materials Design and Architecture to Applications

ABSTRACT Driven by the pursuit of superior therapeutic efficacy and patient autonomy, healthcare is shifting toward proactive “active rehabilitation”. Conductive composite hydrogels, featuring tissue‐mimetic mechanics and multi‐modal sensing capabilities, have emerged as ideal bio‐electronic interfaces for these systems. This review systematically provides a comprehensive overview of hydrogel‐interfaced active rehabilitation systems, progressing from fundamental material design and system architecture to applications. We first outline strategies to enhance hydrogels' biocompatibility, mechanical properties, environmental robustness, self‐adhesion, and conductivity. Next, we delineate the closed‐loop architecture comprising perception, decision, and execution layers, and trace two end‐to‐end demonstrations from ionic‐to‐electronic transduction through algorithmic decoding to physical feedback. Furthermore, we highlight applications in limb motor recovery, swallowing, language, and cognitive rehabilitation, and neural, bone, and tendon regeneration. Finally, we discuss persistent challenges in signal decoupling, material trade‐offs, energy autonomy, and clinical validation, and envision future directions toward AI‐driven personalization, variable‐stiffness hydrogels, self‐powered integration, and standardized benchmarking.

Efficient Acidic CO ₂ Reduction via Local Strain Engineering of Nickel Single‐Atom Catalysts

ABSTRACT Acidic CO 2  reduction reaction (CO 2 RR) enhances carbon efficiency and electrolyzer stability. Although nickel single‐atom catalysts (Ni‐SACs) effectively convert CO 2 into CO in neutral/alkaline conditions, their performance in acid is hindered by the competing hydrogen evolution reaction (HER). Here we show that tailoring the local strain of Ni‐SACs can enhance HER suppression across a broad potential range. Density functional theory calculations indicate that Ni‐SACs with steeper local curvature reduce *COOH adsorption by 0.23 eV while increasing *H adsorption by 0.55 eV. To validate our predictions, we leveraged carbon nanotubes (CNTs) with different diameters to impose controlled local strain on Ni‐SACs. In Ar‐saturated 0.05 M H 2 SO 4 , Ni‐SACs on 5‐nm CNTs (Ni‐CNT5) demonstrate the lowest hydronium and water reduction current density among all types of CNT support. In a flow cell with pH 1 catholyte, Ni‐CNT5 maintains >95% CO Faradaic efficiency (FE) from −1.0 to −2.4 V, in contrast to Ni‐CNT50 with ∼70% FE(H 2 ) at −2.4 V. Owing to its effective HER inhibition, Ni‐CNT5 achieves 80% single‐pass CO 2  conversion efficiency and operates stably in acidic electrolyte with negligible loss in current or selectivity. Our findings expand the toolbox for SACs engineering, highlighting the critical role of local stress for controlled activity.

Sub‐Stoichiometric Supramolecular Co‐Assembly Strategy Enabling Efficient Chirality Transfer and CPL Amplification

ABSTRACT Chirality transfer enables molecular asymmetry to propagate from discrete building blocks into hierarchical assemblies, providing a fundamental framework for engineering functional nanostructures. However, conventional supramolecular co‐assembly typically necessitates stoichiometric or excess guest loading to achieve effective chirality transfer, a requirement that often compromises structural fidelity and chiroptical efficiency due to inefficient stereochemical communication. Here, we report a sub‐stoichiometric co‐assembly strategy wherein trace amounts of an achiral modulator (berberine, BBR) cooperatively intercalate within a chiral supramolecular framework (LPF/DPF; left‐/right‐handed phenylalanine‐based gelators) to induce potent chiroptical amplification. We demonstrate that a minimal guest‐to‐host mole ratio of 0.2 is sufficient to capture and amplify host chirality, yielding luminescence dissymmetry factors (| g lum | ≈ 0.08) an order of magnitude higher than those produced by stoichiometric equivalents. Mechanistic investigations reveal that sparse intercalation at this sub‐stoichiometric threshold preserves the underlying hydrogen‐bonded network while enforcing a precise helical registry through synergistic π–π and electrostatic interactions that ensures thermodynamic stability (Δ G °). While stoichiometric excess results in kinetically trapped, non‐helical aggregates, this sub‐stoichiometric control establishes a robust design principle for translating molecular‐scale interactions into high‐performance chiroptical materials with minimal guest loading.

A Mucosa‐Inspired Dynamic Biointerface Engineering a Biofilm‐Preventive Niche Against Pathogenic Microbiome Dysbiosis

ABSTRACT A stable symbiosis within the microbiome‐host axis is essential for human health. However, preventing microbiome dysbiosis using biomaterials remains challenging due to their unpredictable influence on microbiome evolution. Inspired by the defensive niche of symbiotic mucosa, we have developed a biointerface that forms an engineered mucosa‐inspired dynamic niche to prevent pathogenic dysbiosis. This biointerface features a dynamic zwitterionic network that emulates the mucosa's biophysical defensive functions. Notably, by leveraging its dynamic niche, the biointerface restricts microbial attachment and aggregation, thereby preventing biofilm formation. Comprehensive metagenomic analyses reveal that microbial communities adapt to this biofilm‐preventive dynamic biointerface compositionally and functionally. In particular, Gram‐negative bacteria were relatively reduced, along with decreased abundance of pathways associated with virulence and biofilm formation. Consequently, the mucosa‐inspired biointerface intrinsically prevents the development of pathogenic dysbiosis. This study demonstrates the groundbreaking potential of material‐based niche engineering to guide the ecological shifts of microbial communities from the material scale.

Air‐Processed Perovskite/Silicon Tandem Solar Cells via Iodide Oxidation Suppression

ABSTRACT Efficient wide‐bandgap (WBG) perovskite top cells are essential for high‐performance perovskite/silicon tandem solar cells (TSCs), yet their fabrication in humid ambient air remains difficult because moisture‐ and oxygen‐induced reactions deteriorate film quality and stability. Here, 4‐[[4,6‐bis(octylthio)‐1,3,5‐triazin‐2‐yl]amino]‐2,6‐bis(1,1‐dimethylethyl)‐phenol (BTDP) is introduced into the perovskite precursor to enable WBG perovskite formation under high‐humid ambient air conditions. BTDP scavenges superoxide radical anions, inhibits I − oxidation to I 2 , absorbs ultraviolet light, coordinates with Pb 2+ to regulate crystallization and forms a hydrophobic barrier at surfaces and grain boundaries. With this strategy, blade‐coated WBG perovskite solar cells (PSCs) fabricated at 60% relative humidity deliver a power conversion efficiency (PCE) of 23.45%, which represents the highest PCE reported for air‐processed WBG PSCs with bandgap ≥1.68 eV. Mini‐modules with an aperture area of 14.81 cm 2 reach 20.12% efficiency. Moreover, the method enables ambient‐air fabrication of two‐terminal perovskite/tunnel oxide passivated contact (TOPCon) TSCs with a certified efficiency of 32.59%, among the highest PCEs reported for two‐terminal perovskite/TOPCon TSCs. This study provides a scalable route to efficient, stable single‐junction and tandem perovskite photovoltaics.

An Acid‐Neutralizing Nanoreactor Counteracts Senescence‐Driven Cartilage Degeneration in Osteoarthritis

ABSTRACT Osteoarthritis (OA) is a multifactorial degenerative joint disease characterized by irreversible cartilage deterioration associated with chronic inflammation, oxidative stress, tissue acidosis, and abnormal mechanical loading. During OA progression, inflammation‐associated metabolic reprogramming and hypoxia‐enhanced glycolysis promote lactate accumulation and local acidosis. OA‐associated acidosis may function as an exacerbating factor within this pathological microenvironment by engaging acid‐sensing pathways and contributing to chondrocyte senescence, apoptosis, and SASP‐associated inflammatory amplification, thereby exacerbating cartilage degeneration. Accordingly, therapeutic strategies that actively neutralize pathological acidity while concurrently modulating inflammatory and oxidative stress cascades may provide a more robust, disease‐modifying approach for OA intervention. Herein, we designed a nanoreactor termed OLDH‐DP@POM by integrating mildly alkaline layered double hydroxide (LDH) nanosheets with active acid‐neutralizing capability and anchoring polyoxometalates (POM) with antioxidant activity, thereby enabling coordinated regulation of pathological acidosis and oxidative stress. Meanwhile, lubrication‐enhancing zwitterionic poly(2‐methacryloyloxyethyl phosphorylcholine) (PMPC) polymer brushes were grafted, endowing the nanoreactor with superior joint lubrication and chondroprotective capability. Both in vitro and in vivo results demonstrated that OLDH‐DP@POM effectively neutralized local acidosis at osteoarthritic lesions, substantially ameliorated synovial inflammation, suppressed Piezo‐mediated mechanotransduction, delayed chondrocyte senescence, and ultimately attenuated cartilage degeneration. Overall, this work provides a promising nanotherapeutic platform for disease‐modifying treatment of OA.

Memristive Motion‐Streak Neuron for Spatiotemporal Multiple Object Detection

ABSTRACT Conventional artificial vision systems process dynamic scenes inefficiently by reconstructing motion from discrete frames, which requires post‐processing. In contrast, real‐world environments containing multiple moving objects demand sensor‐level discrimination. This work presents a memristive motion‐streak neuron that performs spatiotemporal encoding by integrating an Al/InGaZnO/Al optomemristor with an Ag/HfO 2 /Pt dynamic memristor, whose relaxation dynamics provide temporal memory. In this system, the presence time of moving objects is detected by decay of the output current, allowing motion direction and speed to be directly inferred from the relaxation behavior. The integrated memristor pixel array enables processing of continuous movements and achieves 96.2% classification accuracy for multiple objects. Also, integrating the motion‐streak neuron with the resistor–capacitor kernel further encodes temporal intervals between optical events, enabling recognition of complex movement patterns. This dynamic processing diminishes computational overhead and provides a hardware solution for next‐generation vision systems.

Enhanced Mechanical Recycling of Polymer Mixtures by a Trifunctional Dynamic Crosslinker

ABSTRACT Mechanical recycling of mixed post‐consumer apolar/polar polymers, due to their mis‐matched polarity and inherent immiscibility, is typically a downcycling process yielding brittle materials. An emerging method that can enhance recycling of such mixtures into dynamically crosslinked, high‐performance thermosets is a dynamic crosslinker (DC) platform; however, current DCs typically require an external catalyst and, due to their insufficiently high peak activation temperature ( T a <190°C), are limited to a subset of applicable polymers and unsuitable for industrial melt‐extrusion processing of high melting temperature ( T m ) polymers. Herein, we report a trifunctional DC incorporating three sought‐after properties: thermally robust pyridotriazole cores as the high‐ T a (245°C) crosslinking sites compatible with reactive extrusion up to 270°C; dynamic siloxane linkages as the robust yet exchangeable bonds; and pyridine/ester functionalities as the internal catalysis sites devoid of external catalysts. Overall, this self‐catalyzed, high‐ T a DC can compatibilize waste plastic mixtures containing high T m polymers and impart the recycled mixtures with superior thermoset properties such as enhanced creep resistance and thermomechanical stability while being melt‐(re)processable.

Mechanistic Insights Into Anionic Doping in O3‑Type Na(NiFeMn) _1/3 O ₂ Cathode

ABSTRACT The lack of mechanistic guidelines hinders rational anionic doping in layered oxide cathodes for sodium‐ion batteries (SIBs). Using O3‐type Na(NiFeMn) 1/3 O 2 as a model and combining experiments with density functional theory (DFT) calculations, we reveal that doping effects are governed by two intrinsic dopant properties: valence‐electron configuration and ionic radius. For radius‐matched dopants, electron‐donating F reduces Fe 3 + , enhancing high‐voltage and air stability, whereas electron‐withdrawing N oxidizes Ni 2 + , accelerating degradation. Oversized (Cl, Br) or mismatched (B) dopants cause structural collapse. This dual‐parameter framework enables predictive design of stable, high‐performance cathodes.

Sandcastle Worm Cement‐Mimicking Underwater Adhesives via Liquid–Liquid Phase Separation and Auto‐Catalyzed Network Strengthening

ABSTRACT Achieving robust underwater adhesion remains challenging due to the interference of interfacial water and insufficient cohesion within conventional adhesives. Inspired by the sandcastle worm's cement forming via liquid–liquid phase separation (LLPS), we developed a novel class of tannic acid/polyethylene glycol/Laponite (TA/PEG/Lap, TPL) composite adhesives to effectively enhance interfacial water repulsion and underwater adhesion. TA and PEG self‐assembled into a dynamic adhesive coacervate matrix via LLPS, while Laponite nanoclays were subsequently introduced as reinforcement fillers and catalysts to trigger polyphenol oxidation, thereby transforming TPL from dynamic soft gel to mechanically robust solid. Specifically, the initially self‐healing TPL can adapt to the irregular surface topography by repelling interfacial water and forming adhesion, thereafter self‐cure to strengthen the mechanical interlocking with irregular substrate surfaces, and eventually realize robust underwater adhesion. Leveraging the transient network reversibility and self‐driven crosslinking stability, the TPL formulations can be processed into injectable, sprayable, coatable, or scaffold forms, offering robust adhesion, fault tolerance, eco‐compatibility, long‐term stability, fire resistance, and antibacterial activity. Overall, this work establishes a paradigm shift in bioinspired design of robust underwater adhesives and highlights the potential of TPL systems for multi‐scenario and multi‐functional applications, including acute hemostasis, soil fixation, infrastructure crack repair, and other underwater sealing tasks.

Topological Amorphization of VO ₂ via Chemical Locking for Durable Aqueous Zinc‐Ion Storage

ABSTRACT Although vanadium‐based oxides are promising cathodes for aqueous zinc‐ion batteries (AZIBs), their rigid crystalline lattices suffer from sluggish ion diffusion and rapid capacity decay caused by vanadium dissolution. Here, we report an organic‐driven topological amorphization strategy to construct a resilient and kinetically accelerated cathode. Using levamisole hydrochloride (LMS) as a dual‐functional modulator, strong Lewis's acid‐base interactions (V─N/V─S coordination) generate localized tensile stress that progressively disrupts the long‐range periodic lattice. This targeted lattice cleavage transforms crystalline VO 2 into a short‐range ordered amorphous sponge (denoted as L‐VO 2 ‐0.1), while preserving nanoclustered motifs interconnected through flexible organic “hinges”. The resulting topological architecture simultaneously reconciles the stability‐kinetics trade‐off, where the isotropic 3D open framework enables fast, sterically unimpeded Zn 2+ transport with capacitor‐like kinetics, while the dynamic organic hinges efficiently accommodate volume strain and thermodynamically suppress vanadium dissolution. Consequently, the L‐VO 2 ‐0.1 cathode delivers 481.6 mAh g −1 at 0.5 A g −1 and sustains 12 000 cycles at an extreme rate of 20 A g −1 with 83.5% capacity retention. Furthermore, a dual‐cathode pouch cell achieves a commercial‐grade absolute capacity of 1.15 Ah and a high areal capacity of 7.9 mAh cm −2 under a stringent mass loading (>20 mg cm −2 ), enabling feasible routes toward scalable, durable energy storage devices.

Helically Chiral Tetradentate Pt(II) Complexes for Simultaneous Deep‐Blue Electroluminescence and Circularly Polarized Luminescence via Diastereoselective Synthesis

ABSTRACT Circularly polarized organic light‐emitting diodes (CP‐OLEDs) have attracted great attention because of their promising applications in 3D displays. However, developing high‐performance CP‐OLEDs typically face the challenge of integrating large‐scale availability of emitters, device efficiency, color purity, and brightness, especially in the deep‐blue spectral region. Herein, we developed a novel strategy to successfully realize the diastereoselective and gram‐scale synthesis of helically chiral tetradentate Pt(II) complexes with high configurational stabilities through a central chirality adaptively induced helical chirality (CAIH) approach. The bulky central chiral moiety facilitates the suppression of intermolecular interactions and increases the color purity and molecular rigidity. R,M ‐PtCam2 showed a quantum efficiency of 99% and high color purity, with a full‐width at half‐maximum (FWHM) of 19.8 nm. R,M ‐PtCam2/ P ‐PtCam2‐based deep‐blue OLEDs successfully displayed obvious and mirror‐image CP electroluminescence signals. R,M ‐PtCam2 CP‐OLED exhibited a high color purity (FWHM = 24 nm) and a high maximum brightness of up to 51592 cd/m 2 ; moreover, it also achieved a maximum external quantum efficiency (EQE) of 33.2%, along with a record‐high EQE of 30.9% at 1000 cd/m 2 for all reported deep‐blue CP‐OLEDs with CIE y < 0.20. This study provides a molecular design strategy to prepare robust helically chiral Pt(II) emitters for high‐performance deep‐blue phosphorescent CP‐OLEDs.

Interfacial Dynamic Oxygen Exchange Preserves C─O Bonds for Selective CO ₂ ‐to‐Ethanol Electrosynthesis

ABSTRACT Intermediate‐valence copper (Cu + ) is essential for preserving C─O bonds during the electrochemical reduction of CO 2 to ethanol, yet its progressive over‐reduction to Cu 0 under operating potentials inevitably dictates C─O bond cleavage and shifts selectivity toward ethylene. Herein, we propose an interfacial dynamic oxygen exchange strategy to stabilize Cu + sites and steer the ethanol reaction pathway. We realize this mechanism by engineering a few‐layer ceria‐coated cuprous oxide (Cu 2 O@CeO 2 ) catalyst featuring an oxygen vacancy‐rich heterointerface (Ce−O V −Cu). Operando spectroscopic measurements and density functional theory calculations reveal that these interfacial oxygen vacancies act as core mediators; by continuously capturing and migrating oxygen species derived from CO 2 , they effectively arrest the reduction of adjacent Cu + siteversuss. Crucially, this dynamic interface dictates the asymmetric C─C coupling of *CH 2 and *CHO, successfully preserving the C−O bond during the subsequent protonation of *CH 2 CHO to *CH 3 CHO. Consequently, the optimized catalyst delivers an outstanding ethanol Faradaic efficiency of 68.5% at −1.1 V versus RHE and exhibits robust operational stability exceeding 150 h, substantially outperforming pristine Cu 2 O. This study establishes vacancy‐mediated dynamic oxygen exchange as a robust strategy for preserving key oxygen‐containing functional groups in highly selective CO 2 ‐to‐ethanol electrosynthesis.